If your moped or scooter is running poorly, the carburetor is often the main culprit.
The carb provides the fuel/air mixture to the engine’s combustion chamber.
Carburetors feature a number of jets and passages for fuel and air to mix and get delivered at different throttle positions.
As you open the throttle more, more fuel and air is provided to the engine.
This is especially in the case of a scooter or moped that has been sitting for a while, or one you’ve picked up as a project to restore.
This page will provide you with a guide to clean out the carburetor and get your bike running well again.
Steps to Clean a Moped Carb
Cleaning a carb can get messy. You’ll also be dealing with old fuel and some nasty cleaning chemicals. Be sure to protect yourself with:
- Eye protection.
- Rags to clean up.
- Fuel safe containers.
- A well-ventilated area.
Cleaning the carburetor on your scooter is a fairly simple process.
If your moped or scooter is running poorly, a clogged carburetor is a likely issue.
Before you get started, you should have a replacement carb kit with new gaskets, jets, and o-rings ready to go. You’ll likely need to replace many of the old parts that have been gummed up overtime, and many of the rubber gaskets will likely be worn out.
You’ll also need:
- A flat-head screwdriver.
- Carb cleaning wires.
- Carb cleaning spray.
- Chemical carb dip.
Step 1: Remove the Carburetor from your Moped
First, you’ll need to remove the carb from the engine.
Unscrew the manifold clamps, throttle cable, and air filter or air box.
How do you remove a carburetor from a moped?
In order to clean your moped’s carb, you’ll first need to remove it.
Most scooters and mopeds will follow the same process. And, you’ll typically only have a single carb to deal with.
The carb is attached to the bike via the:
- Rubber manifold off of the engine’s cylinder block.
- Airbox or air filter.
- Throttle cable.
First, you should turn off the fuel valve and drain the fuel from the float bowl. There should be a drain screw near the bottom of the bowl.
Be sure to wear gloves, and drain the old fuel into a gas-safe container.
Next, loosen the carb’s top cap to remove the throttle cable from the slide. Be careful to keep track of the spring and any washers/gaskets.
Now you’ll be able to unscrew the manifold and air filter clamps.
The carb should come off freely, and you’ll be able to clean it.
For specific instructions for your scooter/moped and carb, you can refer to your bike’s service manual.
Step 2: Take Apart the Carburetor
With the carb off the bike, you’re ready to start the disassembly.
Stay organized and keep track of the parts. You’ll either need to clean and service or replace each jet and gasket.
Unscrew the throttle cap, and remove the throttle slide, spring, and needle jet.
Unscrew the pilot/idle screw from the side of the carb body. There will likely be a spring and washer there as well.
Unscrew the 3-4 screws connecting the float bowl to the bottom of the carb body.
With the float bowl removed, you’ll be able to remove the float pin, floats, and float needle, as well as the rest of the jets.
Step 3: Clean the Carb
With the carb fully disassembled, you’re ready to start cleaning it.
The metal parts and the carb body can be soaked in carb cleaner dip. Berryman’s carb cleaner offers a dip bucket for soaking the carbs for extended periods of time.
A long soak in the cleaning solution will help with gummed up carbs.
Afterwards, you can use a carb spray and cleaning wires to clear each of the small passages throughout the carb.
Step 4: Reassemble
After you’ve thoroughly cleaned the carb, you’re ready to put everything back together.
Install new rubber components and reinstall the jets, floats, carb bowl, and throttle slide in the opposite order as it was disassembled.
If you’re replacing any old jets, be sure to use the same sizes as the ones you are replacing.
Attach the throttle cable, and attach the carb back onto the manifold and air filter.
Once installed, you’ll need to reset the idle screw to get your scooter idling and running properly.
How do you clean a carburetor on a scooter without removing it?
Unfortunately, a proper carb cleaning cannot be achieved without removing it from the bike.
If your carburetor is clogged, you will need to take it apart to clean, and possibly replace, each of the tiny jets and passages throughout the carb’s body.
You can keep your carbs clean by:
- Riding your moped regularly.
- Using a fuel treatment.
Tuning your Moped Carb
If your scooter or moped is still running poorly after a carb cleaning, you may need to take some time to tune it.
Check out some of our carb tuning topics to get starting diagnosing carburetor issues and tuning them:
Related Carb Topics
If you’re looking for more resources on cleaning and tuning your carburetors, MotorcycleZombies.com has you covered. Check out these related guides: